Surgery is not always necessary in intraosseous lipoma.

Intraosseous lipoma is the rarest primary bone tumor, is usually asymptomatic, and is often discovered incidentally during unrelated investigations. Lipomas usually undergo varying degrees of involution, with necrosis, cyst formation, and calcification. Careful radiological-pathological correlation is required to avoid misinterpretation. This study describes 12 intraosseous lipomas in 11 patients (6 men, 5 women; mean age, 36 years [range, 25-50 years]; mean follow-up, 5 years [range, 2-11 years]). The lesions were located in the calcaneus in 7 patients (bilaterally in 1 patient), the tibia in 2, the femur in 1, and the ilium in 1. All lesions were asymptomatic and discovered incidentally except in 4 patients (5 lesions). Curettage and bone grafting were performed after biopsy in 4 lesions; and in 1 patient, curettage, bone grafting, and reconstructive surgery were performed after pathologic fracture. The remaining 7 patients were followed up conservatively. Although definite diagnosis of an intraosseous lesion is possible only by histopathologic examination, computed tomography and magnetic resonance imaging findings of intraosseous lipoma are typical, and most patients' symptoms are relieved by conservative means. For this reason, we believe that in patients with no signs of an impending pathologic fracture or suspicion of malignancy, clinical and radiological follow-up is sufficient. However, since intraosseous lipoma is an uncommon bone tumor, physicians should be familiar with the radiological features of this lesion for the correct diagnosis. Copyright 2010, SLACK Incorporated.